Detergent manufacturers continue to seek to produce solid free-flowing particulate laundry powders having excellent cleaning profiles, good physical properties such as flowability, and that have good dispensing and dissolution profiles. Recent moves in the laundry detergent industry have reduced or even removed builder ingredients such as zeolite builders and phosphate builders. This has resulted in laundry detergent powders having good dispensing and dissolution profiles but the reduction in the builder performance of the product can result in wash solutions being formed that are high in hardness cations. These hardness cations can interact with the surfactants and reduce the cleaning performance of the product. Careful attention has been needed on the surfactant systems used to ensure the surfactants are still able to perform in these high hardness conditions. One such approach has been to incorporate a co-surfactant, such as an alkyl alkoxylated sulphate in addition to a surfactant such as alkyl benzene sulphonate. Such a surfactant system has good hardness tolerancy and ensures good cleaning performance even in conditions of high hardness. However, the incorporation of alkyl alkoxylated sulphate can lead to an unwanted reduction in the solubility profile of the product, and can negate some of the dispensing and solubility benefits achieved by formulating a nil, or low, builder laundry detergent powder.
The inventors have found that the incorporation of an alkyl alkoxylated sulphate having a specific branching, results in a laundry detergent powder having good cleaning performance, even in conditions of high hardness, whilst also having good dissolution and dispensing performance. The inventors have found that this specific branched alkyl alkoxylate sulphate provides good hardness tolerancy without negating the good solubility and dispensing performance of the product.
In addition, the compositions of the present invention provide good fabric-softener stripping performance, providing good multi-cycle benefits on fabric whiteness performance, especially on terry towel fabrics.
The compositions of the present invention also provide good suds stability.